/*
 * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
#include <console.h>
#include <debug.h>
#include <libfdt.h>
#include <psci.h>
#include "qemu_private.h"
#include <string.h>

static int append_psci_compatible(void *fdt, int offs, const char *str)
{
    return fdt_appendprop(fdt, offs, "compatible", str, strlen(str) + 1);
}

int dt_add_psci_node(void *fdt)
{
    int offs;

    if (fdt_path_offset(fdt, "/psci") >= 0) {
        WARN("PSCI Device Tree node already exists!\n");
        return 0;
    }

    offs = fdt_path_offset(fdt, "/");
    if (offs < 0)
        return -1;
    offs = fdt_add_subnode(fdt, offs, "psci");
    if (offs < 0)
        return -1;
    if (append_psci_compatible(fdt, offs, "arm,psci-1.0"))
        return -1;
    if (append_psci_compatible(fdt, offs, "arm,psci-0.2"))
        return -1;
    if (append_psci_compatible(fdt, offs, "arm,psci"))
        return -1;
    if (fdt_setprop_string(fdt, offs, "method", "smc"))
        return -1;
    if (fdt_setprop_u32(fdt, offs, "cpu_suspend", PSCI_CPU_SUSPEND_AARCH64))
        return -1;
    if (fdt_setprop_u32(fdt, offs, "cpu_off", PSCI_CPU_OFF))
        return -1;
    if (fdt_setprop_u32(fdt, offs, "cpu_on", PSCI_CPU_ON_AARCH64))
        return -1;
    if (fdt_setprop_u32(fdt, offs, "sys_poweroff", PSCI_SYSTEM_OFF))
        return -1;
    if (fdt_setprop_u32(fdt, offs, "sys_reset", PSCI_SYSTEM_RESET))
        return -1;
    return 0;
}

static int check_node_compat_prefix(void *fdt, int offs, const char *prefix)
{
    const size_t prefix_len = strlen(prefix);
    size_t l;
    int plen;
    const char *prop;

    prop = fdt_getprop(fdt, offs, "compatible", &plen);
    if (!prop)
        return -1;

    while (plen > 0) {
        if (memcmp(prop, prefix, prefix_len) == 0)
            return 0; /* match */

        l = strlen(prop) + 1;
        prop += l;
        plen -= l;
    }

    return -1;
}

int dt_add_psci_cpu_enable_methods(void *fdt)
{
    int offs = 0;

    while (1) {
        offs = fdt_next_node(fdt, offs, NULL);
        if (offs < 0)
            break;
        if (fdt_getprop(fdt, offs, "enable-method", NULL))
            continue; /* already set */
        if (check_node_compat_prefix(fdt, offs, "arm,cortex-a"))
            continue; /* no compatible */
        if (fdt_setprop_string(fdt, offs, "enable-method", "psci"))
            return -1;
        /* Need to restart scanning as offsets may have changed */
        offs = 0;
    }
    return 0;
}
